Ventricular catheters are widely used in various procedures including the collection of cerebrospinal fluid, introduction of contrast medium or chemotherapy, the measurement of intracranial pressure and the treatment of hydrocephalus. The proper positioning of the catheter in the ventricular system is facilitated by the use of a rigid stylet or the use of an optical endoscope.
The catheters are generally constructed of silicone elastomer tubing and have a series of fluid flow apertures adjacent the distal end and a slit at the distal end. The slit is capable of opening to permit the terminal end of a stylet or optical endoscope to pass through the slit to properly position the catheter. When the catheter is in the desired position in the ventricle, the stylet or optical endoscope can be removed while leaving the catheter in position. These types of catheters are disclosed in U.S. Pat. Nos. 5,437,626; 5,690,117 and 5,738,666, the disclosures of which are incorporated herein by reference.
One of the difficulties in the use of slit catheters is the tendency of the edges of the catheter adjacent the slit be adhered together or knit together during sterilization or storage and close the slit so that a stylet or optical endoscope cannot be passed through the slit to aid in positioning of the catheter.